Polymer-dispersed polyol and process for producing flexible polyurethane foam

ABSTRACT

To provide a process for producing a flexible polyurethane foam having a higher biomass degree than a conventional flexible polyurethane foam and excellent in foam physical properties and its appearance. 
     A polymer-dispersed polyol obtained by polymerizing a vinyl monomer in the presence of the following polyol (a1) derived from a natural fat/oil and/or the following polyoxyalkylene polyol (a2) is used: Polyol (a1) derived from a natural fat/oil: a polyol derived from a natural fat/oil, which is obtained by providing a natural fat/oil with hydroxy groups by chemical reaction, and which has a hydroxy value of from 20 to 250 mgKOH/g and a molecular weight distribution of at least 1.2; Polyoxyalkylene polyol (a2): a polyoxyalkylene polyol which is produced by ring-opening polymerization of an alkylene oxide (c) with the polyol (a1) derived from a natural fat/oil in the presence of at least one polymerization catalyst (b) selected from the group consisting of a coordination anionic polymerization catalyst and a cationic polymerization catalyst.

TECHNICAL FIELD

The present invention relates to a polymer-dispersed polyol using a rawmaterial derived from a natural fat/oil, and a process for producing aflexible polyurethane foam using the polymer-dispersed polyol.

BACKGROUND ART

A flexible polyurethane foam is produced by reacting a polyol and apolyisocyanate in the presence of e.g. a catalyst and a blowing agent.As the polyol, e.g. a polyoxyalkylene polyol produced by ring-openingpolymerization of an alkylene oxide such as ethylene oxide or propyleneoxide to an initiator having an active hydrogen atom, or apolymer-dispersed polyol obtained by polymerizing a vinyl monomer in thepresence of the polyoxyalkylene polyol, is used. The alkylene oxide andthe vinyl monomer accounting for a large part of initiators which areraw materials of the polyol, are compounds derived from petroleum.

In recent years, in consideration of environment, there has been ademand to increase the proportion of a non-petroleum type raw materialin a polyol (hereinafter referred to as the biomass degree).

As the polyol using a non-petroleum type raw material, the followingpolymer-dispersed polyols are proposed.

(1) A polymer-dispersed polyol obtained by polymerizing a reactionmixture containing a vinyl monomer, a polyol and a modified hydroxygroup-containing compound obtained by reacting castor oil with a polyol(Patent Document 1).

(2) A polymer-dispersed polyol having polymer particles obtained bypolymerizing a vinyl monomer dispersed in a polyol containing a polyolderived from a plant (castor oil) and a low-monool-content polyol(Patent Document 2).

(3) A polymer-dispersed polyol having polymer particles dispersed in apolyolester polyol having hydroxymethyl groups, induced from a fattyacid or a fatty acid ester derived from a vegetable oil plant (PatentDocument 3).

However, since the polymer-dispersed polyols in (1) and (2) containpolyols derived from petroleum in a large amount, the biomass degreesare not sufficiently high. Further, if the proportion of castor oil,which is a non-petroleum type raw material, is increased, it is notpossible to produce a flexible polyurethane foam excellent in foamphysical properties and its appearance. With respect to thepolymer-dispersed polyol in (3), the production process of a polyesterpolyol having hydroxymethyl groups is long, whereby the cost tends to behigh.

Patent Document 1: JP-A-9-31142

Patent Document 2: W02007/020904

Patent Document 3: W02006/065345

DISCLOSURE OF THE INVENTION Object to be Accomplished by the Invention

The present invention provides a polymer-dispersed polyol with which aflexible polyurethane foam excellent in foam physical properties and itsappearance even with a higher biomass degree than a conventionalpolymer-dispersed polyol can be produced, and a process for producing aflexible polyurethane foam having a higher biomass degree than aconventional flexible polyurethane foam and excellent in foam physicalproperties and its appearance.

Means to Accomplish the Object

The polymer-dispersed polyol of the present invention is characterizedby being obtained by polymerizing a vinyl monomer in the presence of thefollowing polyol (a1) derived from a natural fat/oil and/or thefollowing polyoxyalkylene polyol (a2).

Polyol (a1) derived from a natural fat/oil: a polyol derived from anatural fat/oil, which is obtained by providing a natural fat/oil withhydroxy groups by chemical reaction, and which has a hydroxy value offrom 20 to 250 mgKOH/g and a molecular weight distribution of at least1.2; Polyoxyalkylene polyol (a2): a polyoxyalkylene polyol which isproduced by ring-opening polymerization of an alkylene oxide (c) withthe polyol (a1) derived from a natural fat/oil in the presence of atleast one polymerization catalyst (b) selected from the group consistingof a coordination anionic polymerization catalyst and a cationicpolymerization catalyst.

The polyol (a1) derived from a natural fat/oil is preferably oneobtained by blowing air or oxygen in a natural fat/oil to causeoxidative crosslinking between unsaturated double bonds of the naturalfat/oil and at the same time, to have hydroxy groups provided, or oneobtained by epoxidizing unsaturated double bonds of a natural fat/oil byhaving an oxidizing agent acted thereto, followed by ring-opening in thepresence of an active hydrogen compound to have hydroxy groups provided.

The natural fat/oil preferably has an iodine value of from 50 to 200.

The method for producing a flexible polyurethane foam of the presentinvention is characterized by reacting a polyol (A) containing thepolymer-dispersed polyol (A1) of the present invention and apolyisocyanate (B) in the presence of a catalyst (C) and a blowing agent(D).

The polyol (A) preferably further contains a polyoxyalkylene polyol (A2)having an average number of hydroxy groups of from 2 to 8 and a hydroxyvalue of from 20 to 160 mgKOH/g.

The polyol (A) preferably further contains the polyoxyalkylene polyol(a2).

Effect of Invention

According to the polymer-dispersed polyol of the present invention, itis possible to produce a flexible polyurethane foam excellent in foamphysical properties and its appearance even with a higher biomass degreethan a conventional polymer-dispersed polyol.

According to the process for producing a flexible polyurethane foam ofthe present invention, it is possible to produce a flexible polyurethanefoam having a higher biomass degree than the one of a conventionalflexible polyurethane foam and excellent in foam physical properties andits appearance.

Best Mode for Carrying out the Invention <Polymer-Dispersed Polyol (A1)>

The polymer-dispersed polyol is a polyol wherein polymer particles(dispersoid) obtained by polymerizing a vinyl monomer are dispersed in abase polyol (dispersion medium).

The polymer-dispersed polyol (A1) of the present invention is obtainedby polymerizing a vinyl monomer in the presence of a polyol (a1) derivedfrom a natural fat/oil and/or a polyoxyalkylene polyol (a2).

(Polyol (a1) Derived From a Natural Fat/Oil)

The polyol (a1) derived from a natural fat/oil is the following polymerobtained by providing a natural fat/oil having no hydroxy groups withhydroxy groups by chemical reaction.

The natural fat/oil having no hydroxy groups means a natural fat/oilhaving no hydroxy groups contained slightly as impurities or hydroxygroups obtained by oxidization of double bounds of a hydrolyzate and/orof an unsaturated aliphatic acid obtained by unexpected naturaloxidization.

The polyol (a1) derived from a natural fat/oil is preferably oneobtained by blowing air or oxygen in a natural fat/oil to causeoxidative crosslinking between unsaturated double bonds and at the sametime, to have hydroxy groups provided, or one obtained by epoxidizingunsaturated double bonds of a natural fat/oil by having an oxidizingagent acted thereto, followed by ring-opening in the presence of anactive hydrogen compound to have hydroxy groups provided.

The natural fat/oil may, for example, be a natural fat/oil having nohydroxy groups i.e. natural fat/oil other than castor oil and purifiedphytosterol. Further, since phytosterol is a sterol derived from a plantand is slightly contained in vegetable oil such as soybean oil or canolaoil, inclusion in such a range is acceptable.

The natural fat/oil is preferably one containing an aliphatic acidglyceride having unsaturated double bonds. The natural fat/oil may, forexample, be linseed oil, safflower oil, soybean oil, tung oil, poppyoil, canola oil, sesame oil, rice oil, camellia oil, olive oil, talloil, palm oil, cotton oil, corn oil, fish oil, beef tallow or lard.

The natural fat/oil (it may be used alone or in combination as a mixtureof two or more of them) has an iodine value of preferably from 50 to200, more preferably from 100 to 150 by the measurement in accordancewith JIS K 0070. When the iodine value is at least 50, the reactivitywhen the unsaturated double bonds are provided with hydroxy groups tendsto be high, and more hydroxy groups can be introduced.

The natural fat/oil having an iodine value of at least 50 may, forexample, be linseed oil, safflower oil, soybean oil, tung oil, poppyoil, canola oil, sesame oil, rice oil, camellia oil, olive oil, talloil, cotton oil, corn oil, fish oil or lard.

The natural fat/oil having an iodine value of at least 100 may, forexample, be linseed oil, safflower oil, soybean oil, tung oil, poppyoil, canola oil, sesame oil, rice oil, tall oil, cotton oil, corn oil orfish oil, and soybean oil is preferred since it is inexpensive.

The polyol (a1) derived from a natural fat/oil has a hydroxy value offrom 20 to 250 mgKOH/g, preferably from 30 to 200 mgKOH/g. The castoroil usually has a hydroxy value of from 155 to 177 mgKOH/g. A naturalfat/oil other than castor oil and phytosterol has a hydroxy value of atmost 10 mgKOH/g since it has no hydroxy groups. By providing the naturalfat/oil having no hydroxy groups with hydroxy groups by chemicalreaction, it is possible to adjust the hydroxy value to from 20 to 250mgKOH/g.

When the polyol (a1) derived from a natural fat/oil has a hydroxy valueof at least 20 mgKOH/g, the crosslinking reactivity tends to be high,whereby sufficient foam physical properties can be obtained. When thepolyol (a1) derived from a natural fat/oil has a hydroxy value of atmost 250 mgKOH/g, the flexibility of the obtained flexible polyurethanefoam tends to be excellent and the biomass degree tends to be high.

The polyol (a1) derived from a natural fat/oil has a molecular weightdistribution of at least 1.2. Castor oil or phytosterol has a molecularweight distribution of at most 1.1. However, if a natural fat/oil otherthan castor oil and phytosterol is provided with hydroxy groups bychemical reaction, the molecular weight distribution becomes at least1.2, and making it smaller than that is difficult with currenttechnologies.

The polyol (a1) derived from a natural fat/oil has a molecular weightdistribution of preferably at most 20, more preferably at most 15, fromthe viewpoint of flowability of the polyol. The polyol (a1) derived froma natural fat/oil has a molecular weight distribution of more preferablyfrom 1.2 to 15.

The molecular weight distribution is a ratio (Mw/Mn) of a weight averagemolecular weight (Mw) to a number average molecular weight (Mn).

The polyol (a1) derived from a natural fat/oil has a weight averagemolecular weight (Mw) of preferably at least 1,500, more preferably atleast 1,700, further preferably at least 2,000, from the viewpoint ofthe compatibility or foam physical properties of the polyol.

The polyol (a1) derived from a natural fat/oil has a weight averagemolecular weight (Mw) of preferably at most 500,000, more preferably atmost 100,000, from the viewpoint of flowability of the polyol.

The number average molecular weight (Mn) and the weight averagemolecular weight (Mw) are molecular weights calculated as polystyrene,measured by using a commercially available gel permeation chromatography(GPC) measuring device.

A method for producing the polyol (a1) derived from a natural fat/oilmay, for example, be the following methods (i) to (v), and the method(i) or (ii) is preferred from the viewpoint of the cost.

(i) A method wherein air or oxygen is blown in a natural fat/oil.

(ii) A method wherein after a natural fat/oil is epoxidized, the epoxyrings are ring-opened to have hydroxy groups provided.

(iii) A method wherein after unsaturated double bonds of a naturalfat/oil are reacted with carbon monoxide and hydrogen in the presence ofa special metal catalyst to form carbonyl, hydrogen is further reactedtherewith to have primary hydroxy groups provided.

(iv) A method wherein after the method (i), the method (ii) or (iii) iscarried out to provide remained double bonds with hydroxy groups.

(v) A method wherein after the method (ii) or (iii), the method (i) iscarried out to provide remained double bonds with hydroxy groups.

Method (i):

This is a method wherein by blowing air or oxygen in a natural fat/oilto cause oxidative crosslinking between unsaturated double bonds and atthe same time, to have hydroxy groups provided. Further, a polyhydricalcohol may be introduced by a transesterification reaction.

In method (i), depending on the type of a natural oil/fat to be used asa raw material and the oxidation state during blowing, the molecularweight and the hydroxy value of the polyol (a1) derived from a naturalfat/oil may be adjusted.

In a case where soybean oil is used as a raw material in method (i), theweight average molecular weight (Mw) of the polyol (a1) derived from anatural fat/oil is usually at least 1,500, preferably from 1,700 to500,000, more preferably from 2,000 to 100,000. When the weight averagemolecular weight (Mw) of the polyol (a1) derived from a natural fat/oilis at least 1,500, oxidative crosslinking and hydroxy groups aresufficiently formed, and crosslinkability tends to be good. When theweight average molecular weight (Mw) of the polyol (a1) derived from anatural fat/oil is at most 500,000, the flowability of the polyol tendsto be good.

In a case where soybean oil is used as a raw material in method (i), themolecular weight distribution (Mw/Mn) of the polyol (a1) derived from anatural fat/oil is usually at least 1.2, preferably from 1.5 to 15.

The commercial products of the polyol (a1) derived from a naturalfat/oil (aerated soybean oil) produced by method (i) using soybean oilas a raw material may, for example, be Soyol series manufactured byUrethane Soy Systems Company.

Method (ii):

This is a method wherein unsaturated double bonds of a natural fat/oilare epoxidized by having an oxidizing agent acted thereto, followed byring-opening in the presence of an active hydrogen compound to havehydroxy groups provided by using a cationic polymerization catalyst.

As the oxidizing agent, a peroxide such as peracetic acid is used.

As the cationic polymerization catalyst, boron trifluoride diethyletherate (BF₃Et₂O) may be mentioned.

As the active hydrogen compound, the following compounds are mentioned.

Water, a monohydric alcohol, a polyhydric alcohol, a saccharide, apolyoxyalkylene monool, a polyoxyalkylene polyol, a polyester polyol, apolyetherester polyol, a monovalent carboxylic acid, a multivalentcarboxylic acid, hydroxycarboxylic acid and/or its condensate, a primaryamine, a secondary amine, hydroxy amine, alkanol amine may, for example,be mentioned. From the viewpoint of its low cost and easiness ofhandling, water and/or a monohydric alcohol are preferred, and waterand/or methanol are particularly preferred.

The reaction to provide hydroxy groups by ring-opening the epoxidizedsoybean oil, can be carried out by a process wherein after dropwiselyadding the epoxidized soybean oil is dropwise added to a mixed solutionof the cationic polymerization catalyst and the active hydrogencompound, the cationic polymerization catalyst is removed by anadsorption filtration.

The commercial products of the epoxidized soybean oil may, for example,be ADK CIZER O-130P manufactured by ADEKA Corporation.

In method (ii), it is possible to adjust the hydroxy value of the polyol(a1) derived from a natural fat/oil by the epoxy equivalent of anepoxidized natural fat/oil. It is possible to adjust the epoxyequivalent of an epoxidized natural fat/oil by e.g. the iodine value ofa natural fat/oil used as a raw material, the amount of the oxidizingagent to the iodine value and reactivity.

In method (ii), it is possible to adjust the molecular weight of thepolyol (a1) derived from a natural fat/oil by the amount of the activehydrogen compound during providing hydroxy groups. If the amount of theactive hydrogen compound is remarkably large, it is possible to make themolecular weight small, however, the reactivity tends to be bad and thecost tends to be high. Further, as soon as the molecular weightdistribution becomes less than 1.2, drawbacks occur such that themolecular weight between crosslinking points is also decreased and theflexibility of the obtained flexible polyurethane foam is decreased. Ifthe amount of the active hydrogen compound is too small, a ring-openingpolymerization reaction of the epoxidized natural fat/oil may proceed,whereby the molecular weight may rapidly be increased, and the moleculesmay be gelled.

In a case where epoxidized soybean oil is used as a raw material inmethod (ii), the weight average molecular weight (Mw) of the polyol (a1)derived from a natural fat/oil is usually at least 1,500, preferablyfrom 1,800 to 20,000.

In a case where epoxidized soybean oil is used as a raw material inmethod (ii), the molecular weight distribution (Mw/Mn) of the polyol(a1) derived from a natural fat/oil is usually at least 1.1, preferablyfrom 1.2 to 8.

(Polyoxyalkylene Polyol (a2))

The polyoxyalkylene polyol (a2) a polyoxyalkylene polyol produced byring-opening polymerization of an alkylene oxide (c) with the polyol(a1) derived from a natural fat/oil in the presence of a polymerizationcatalyst (b).

The polymerization catalyst (b) may be at least one selected from acoordination anionic polymerization catalyst and a cationicpolymerization catalyst, and the coordination anionic polymerizationcatalyst is preferred.

The coordination anionic polymerization catalyst may be a knowncoordination anionic polymerization catalyst and is preferably a doublemetal cyanide complex catalyst having an organic ligand (hereinafter thedouble metal cyanide complex catalyst having an organic ligand will bereferred to as a DMC catalyst).

The DMC catalyst can be produced by a known production process (forexample, a method disclosed in JP-A-2003-165836, JP-A-2005-15786,JP-A-7-196778 or JP-A-2000-513647).

The process for producing the DMC catalyst may, for example, be thefollowing processes (α) to (γ).

(α) A process wherein in an aqueous solution, an organic ligand iscoordinated to a reaction product obtained by reacting a halogenatedmetal salt with an alkali metal cyanometalate, followed by separation ofa solid component, and the separated solid component is further washedwith an organic ligand aqueous solution.

(β) A process wherein in the organic ligand aqueous solution, a reactionproduct (a solid component) obtained by reacting a halogenated metalsalt with an alkali metal cyanometalate, is separated, and the separatedsolid component is further washed with the organic ligand aqueoussolution.

(γ) A process wherein in the process (α) or (β), a DMC catalyst in aslurry form is prepared in such a manner that a cake (a solid component)obtained by washing and filtrating/separating the above reactionproduct, is redispersed in the organic ligand aqueous solutioncontaining at most 3 mass % of a polyether compound based on the cake,followed by distillating a volatile component. As the DMC catalyst, theDMC catalyst in a slurry form obtained by process (γ) is preferred fromthe viewpoint of its high reactivity and easiness of handling.

The polyether compound to be used in the process (γ) is preferably apolyether polyol or a polyether monool, and it is more preferably apolyether monool or a polyether polyol, which is produced byring-opening polymerization of an alkylene oxide with an initiator (apolyhydric alcohol or a monoalcohol) by using an alkali catalyst or acationic catalyst, and which has from 1 to 12 average hydroxy groups permolecule and has a weight average molecular weight of from 300 to 5,000.

As the DMC catalyst, a zinc hexacyanocobaltate complex having an organicligand is preferred.

The organic ligand may, for example, be an alcohol, an ether, a ketone,an ester, an amine or an amide. Specifically, it may, for example, betert-butyl alcohol, n-butyl alcohol, iso-butyl alcohol, tert-pentylalcohol, iso-pentyl alcohol, N,N-dimethylacetamide, ethylene glycolmono-tert-butyl ether, ethylene glycol dimethyl ether (glyme),diethylene glycol dimethyl ether (diglyme), triethylene glycol dimethylether (triglyme), iso-propyl alcohol or a dioxane.

The dioxane may be 1,4-dioxane or 1,3-dioxane, and 1,4-dioxane ispreferred.

Such organic ligands may be used alone or in combination as a mixture oftwo or more of them.

The organic ligand is preferably tert-butyl alcohol. Therefore, as theDMC catalyst, it is preferred to use a double metal cyanide complexcatalyst having tert-butyl alcohol as at least one part of the organicligand. Such a DMC catalyst provides high activity and it is therebypossible to produce a polyoxyalkylene polyol (a2) having a low totalunsaturation value. Further, when a DMC catalyst having high activity isused, the amount of the polymerization catalyst can be reduced, wherebythe polyether before purification has little remaining polymerizationcatalyst, and thus it is possible to further reduce the remainingpolymerization catalyst in the polyol after purification.

The cationic polymerization catalyst may, for example, be leadtetrachloride, tin tetrachloride, titanium tetrachloride, aluminumtrichloride, zinc chloride, vanadium trichloride, antimony trichloride,metal acetylacetonate, phosphorus pentafluoride, antimony pentafluoride,boron trifluoride, a boron trifluoride-coordinated compound (forexample, boron trifluoride diethyl etherate, boron trifluoride dibutyletherate, boron trifluoride dioxanate, boron trifluoride aceticanhydride or a boron trifluoride triethylamine complex compound); aninorganic acid (for example, perchloric acid, acetyl perchlorate ortert-butyl perchlorate); an organic acid (for example, hydroxyaceticacid, trichloroacetic acid, trifluoroacetic acid, p-toluene sulfonicacid or trifluoromethane sulfonic acid); a metal salt of an organicacid; a composite salt compound (for example, triethyloxoniumtetrafluoroborate, triphenylmethyl hexafluoroantimonate, allyldiazoniumhexafluorophosphate or allyldiazonium tetrafluoroborate); an alkyl metalsalt (for example, diethylzinc, triethylaluminum or diethylaluminumchloride); heteropolyacid, isopolyacid; or an aluminum or a boroncompound having at least one aromatic hydrocarbon group containing afluorine atom or an aromatic hydrocarbon oxy group containing a fluorineatom.

Among them, preferred is MoO₂(diketonate)Cl, MoO₂(diketonate)OSO₂CF₃,trifluoromethanesulfonic acid, boron trifluoride, a boron trifluoridecoordinated compound (boron trifluoride diethyl etherate, borontrifluoride dibutyl etherate, boron trifluoride dioxanate, borontrifluoride acetic anhydrate or a boron trifluoride triethylaminecomplex compound) or an aluminum or a boron compound having at least onearomatic hydrocarbon group containing a fluorine atom or an aromatichydrocarbon oxy group containing a fluorine atom.

The aromatic hydrocarbon group containing a fluorine atom may, forexample, be pentafluorophenyl, tetrafluorophenyl, trifluorophenyl,3,5-bis(trifluoromethyl)trifluorophenyl, 3,5-bis(trifluoromethyl)phenyl,β-perfluoronaphthyl and 2,2′,2″-perfluorobiphenyl.

The aromatic hydrocarbon oxy group containing a fluorine atom ispreferably a hydrocarbon oxy group having an oxygen atom bonded to theabove aromatic hydrocarbon group containing a fluorine atom.

The aluminum or boron compound having at least one aromatic hydrocarbongroup containing a fluorine atom or an aromatic hydrocarbon oxy groupcontaining a fluorine atom, is preferably a boron compound or analuminum compound as a Lewis acid, described in, for example,JP-A-2000-344881, JP-A-2005-82732 or WO03/000750, or a boron compound oran aluminum compound as an onium salt, described in JP-A-2003-501524 orJP-A-2003-510374.

The Lewis acid may, for example, be tris(pentaflorophenyl)borane,tris(pentaflorophenyl)aluminum, tris(pentaflorophenyloxy)borane andtris(pentaflorophenyloxy)aluminum, and tris(pentaflorophenyl)borane isparticularly preferred since it has high activity.

A counter cation of the onium salt is preferably trityl cation oranilinium cation.

The onium salt is particularly preferably trityltetrakis(pentafluorophenyl)borate or N,N′-dimethylaniliniumtetrakis(pentafluorophenyl)borate.

The alkylene oxide (c) may be a ring-opening polymerizable alkyleneoxide, and ethylene oxide, propylene oxide, styrene oxide, butyleneoxide or cyclohexene oxide may be mentioned. The alkylene oxide (c) maybe used alone or in combination as a mixture of two or more of them.

As the alkylene oxide (c), it is preferred to use propylene oxide andmore preferred to use ethylene oxide and propylene oxide in combination.The ratio of propylene oxide to ethylene oxide (propylene oxide/ethyleneoxide) is preferably from 100/0 to 20/80 (molar ratio) (100/0 to 25/75(the mass ratio)), more preferably from 100/0 to 40/60 (molar ratio)(100/0 to 47/53) (the mass ratio)), further preferably from 100/0 to50/50 (molar ratio) (100/0 to 57/43) (the mass ratio)), particularlypreferably from 99/1 to 60/40 (molar ratio) (99/1 to 66/34) (the massratio)).

As compared with a case where only propylene oxide is used, whenpropylene oxide and ethylene oxide are used in combination, theproportion of terminal primary hydroxy groups of the polyoxyalkylenepolyol (a2) becomes larger. In the polyoxyalkylene polyol (a2), theproportion of the terminal primary hydroxy groups is preferably from 1to 60 mol % based on the total number of hydroxy groups per molecule ofthe polyol.

In the total mass of propylene oxide and ethylene oxide (100 mass %),when the proportion of ethylene oxide is at most 75 mass %, thereactivity of the polyol (A) with the polyisocyanate (B) becomes properand moldability of a flexible polyurethane foam becomes good.

When the polyoxyalkylene polyol (a2) is produced, it is permitted thatanother cyclic compound other than the alkylene oxide (c) is present.

Such another cyclic compound may, for example, be a cyclic ester(ε-caprolactone, lactide or the like), or a cyclic carbonate (ethylenecarbonate, propylene carbonate, neopentyl carbonate or the like).Another cyclic compound may be random-polymerizable orblock-polymerizable.

As another cyclic compound, it is preferred to use a lactide derivedfrom lactic acid obtained by fermentation of sugar derived from a plant,since it is thereby possible to increase the biomass degree in thepolyoxyalkylene polyol (a2).

The process for producing the polyoxyalkylene polyol (a2) may, forexample, be the following process (I) or (II).

(I) A process wherein into a pressure proof reactor equipped with astirrer and a cooling jacket, the polyol (a1) derived from a naturalfat/oil is introduced and a coordination anionic polymerization catalystis added, and then the alkylene oxide (c) is added to ring-openingpolymerization.

(II) A process wherein into a pressure proof reactor equipped with astirrer and a cooling jacket, the polyol (a1) derived from a naturalfat/oil is introduced and a cationic polymerization catalyst is added,and then the alkylene oxide (c) is added to ring-opening polymerization.

Process (I)

As the amount of the coordination anionic polymerization catalyst ismade smaller, it is possible to reduce the amount of the coordinationanionic polymerization catalyst to be contained in the polyoxyalkylenepolyol (a2). As a result, it is possible to suppress the influence ofthe coordination anionic polymerization catalyst on the reactivity ofthe polyol (A) with the polyisocyanate (B) and the foam physicalproperties.

Usually, the coordination anionic polymerization catalyst is removedfrom the polyoxyalkylene polyol (a2). However, in a case where theamount of the coordination anionic polymerization catalyst remained inthe polyoxyalkylene polyol (a2) is small, it is possible to use thepolyoxyalkylene polyol (a2) directly without carrying out the step ofremoving the coordination anionic polymerization catalyst, whereby it ispossible to increase the production efficiency of the polyoxyalkylenepolyol (a2).

The amount of the coordination anionic polymerization catalyst is set sothat a solid catalyst component in the polymerization catalyst(component having a polyether compound, excess ligand, etc. in a slurryremoved) is present in an amount of preferably from 10 to 150 ppm in thepolyoxyalkylene polyol (a2) immediately after the production. When theamount of the solid catalyst component of the polymerization catalystcontained in the polyoxyalkylene polyol (a2) is at least 10 ppm,sufficient activity will be obtained. If the amount of the solidcatalyst component of the polymerization catalyst contained in thepolyoxyalkylene polyol (a2) exceeds 150 ppm, it is not economical.

The ring-opening polymerization temperature is preferably from 30 to180° C., more preferably from 70 to 160° C., particularly preferablyfrom 90 to 140° C. When the ring-opening polymerization temperature isat least 30° C., ring-opening polymerization of the alkylene oxide (c)will sufficiently proceed. When the ring-opening polymerizationtemperature is at most 180° C., it is possible to suppress the decreaseof the activity of the polymerization catalyst.

As the method for removing the coordination anionic polymerizationcatalyst from the polyoxyalkylene polyol (a2), the following method (δ)or (ε) may be mentioned, and the method (δ) is preferred since thehydrolysis will not proceed.

(δ) A method wherein the polymerization catalyst is adsorbed by using anadsorbent (for example, a synthetic silicate (such as magnesium silicateor aluminum silicate), an ion-exchange resin or an activated clay), andthe adsorbent is then removed by filtration.

(ε) A method wherein the polymerization catalyst is neutralized by usinga neutralizer (for example, an amine, an alkali metal hydroxide, anorganic acid or a mineral acid), followed by removal by filtration.

Process (II)

As the process (II), the following process (II-1) is preferred.

(II-1) A process of using, as the cationic polymerization catalyst, atleast one member selected from an aluminum or boron compound having atleast one fluorine-substituted phenyl group or fluorine-substitutedphenoxy group, in a case where the alkylene oxide (c) has at least 3carbon atoms.

The amount of the cationic polymerization catalyst in the process (II-1)is preferably from 10 to 120 ppm, more preferably from 20 to 100 ppm,based on the polyol (a1) derived from a natural fat/oil. From theviewpoint of the purification and the cost of the polyoxyalkylene polyol(a2), the amount of the cationic polymerization catalyst is preferablyas small as possible. However, when the amount of the cationicpolymerization catalyst is at least 10 ppm, the ring-openingpolymerization rate of the alkylene oxid (c) becomes properly high.

In the process (II-1), it is preferred to ring-opening polymerizepreferably from 1 to 30 molecules of the alkylene oxide (c), morepreferably from 1 to 20 molecules of the alkylene oxide (c),particularly preferably from 2 to 15 molecules of the alkylene oxide(c), per hydroxy group of the polyol (a1) derived from a naturalfat/oil. When the number of molecules of the alkylene oxide (c) is atleast 2 per hydroxy group of the polyol (a1) derived from a naturalfat/oil, it becomes easier to make the proportion of the primary hydroxygroups in the total terminal hydroxy groups of the polyoxyalkylenepolyol (a2) to a level of more than 45%. Further, it is thereby possibleto reduce the amount of a multimer as the by-product.

In the process (II-1), it is preferred to maintain the temperatureinside of the reactor at a specific temperature by cooling the reactorand adjusting the supplying rate of the alkylene oxide (c) to thereactor. The temperature inside of the reactor is usually from −15 to140° C., preferably from 0 to 120° C., more preferably from 20 to 90° C.The ring-opening polymerization time is usually from 0.5 to 24 hours,preferably from 1 to 12 hours.

Commonality in the Processes (I) and (II)

In the ring-opening polymerization of the alkylene oxide (c), one typeof the alkylene oxide (c) may be homopolymerized, or two or more type ofthe alkylene oxide (c) may be block polymerized and/or randompolymerized.

The ring-opening polymerization of the alkylene oxide (c) is preferablycarried out under a good stirring condition. When a stirring method ofusing a usual stirring blade, is used, it is preferred to increase therotational speed of the stirring blade within a range not to deterioratethe stirring efficiency by inclusion of a large amount of gas of a gasphase taken into the reaction liquid.

Further, it is preferred to reduce the supplying rate of the alkyleneoxide (c) to the reactor, as much as possible, from the viewpoint thatthe molecular weight distribution of the polyoxyalkylene polyol (a2) canbe narrowed. Further, if the supplying rate is too low, the productionefficiency will be deteriorated. Therefore, it is preferred to set thesupplying rate of the alkylene oxide (c) taking these factors intoconsideration.

The ring-opening polymerization of the alkylene oxide (c) can be carriedout in a solvent.

The solvent may, for example, be an aliphatic hydrocarbon (such ashexane, heptane or cyclohexane) an aromatic hydrocarbon (such asbenzene, toluene or xylene) or a halogen type solvent (such aschloroform or dichloromethane).

An antioxidant, an anticorrosive or the like may be added to thepolyoxyalkylene polyol (a2) to prevent deterioration during storage fora long period of time.

The polyoxyalkylene polyol (a2) has a hydroxy value of preferably from15 to 250 mgKOH/g, more preferably from 20 to 200 mgKOH/g.

The polyoxyalkylene polyol (a2) has a weight average molecular weight(Mw) of preferably from 1,500 to 500,000, more preferably from 1,500 to300,000, particularly preferably from 2,000 to 100,000.

The polyoxyalkylene polyol (a2) has a molecular weight distribution(Mw/Mn) of preferably from 1.2 to 20, more preferably from 1.2 to 15.

The polyoxyalkylene polyol (a2) more preferably has a hydroxy value offrom 15 to 250 mgKOH/g and a molecular weight distribution of from 1.2to 20.

(Vinyl Monomer)

The vinyl monomer may, for example, be acrylonitrile, styrene, amethacrylate or an acrylate. The vinyl monomer may be used alone or incombination as a mixture of two or more of them. The vinyl monomer ispreferably a combination of acrylonitrile and styrene.

Further, in order to control the surface condition, shape and particlesize distribution of polymer particles in the polymer-dispersed polyol,it is possible to use, as a vinyl monomer having ahigh-molecular-weight, a mono(meth)acrylate having repeating units in arequired amount, e.g. a long chain alkyl (meth)acrylate having at least8 carbon atoms, a hydroxy group-terminated polyalkylene glycolmono(meth)acrylate, an alkyl group-terminated polyalkylene glycolmono(meth)acrylate, a hydroxy group-terminated polycarbonatemono(meth)acrylate, an alkyl group-terminated polycarbonatemono(meth)acrylate, an alkyl group-terminated polycaprolactonemono(meth)acrylate, a hydroxy group-terminated polycaprolactonemono(meth)acrylate, an alkyl group-terminated polyether (one having atleast 3 carbon atoms in a carbon linear moiety of repeating units)mono(meth)acrylate or a hydroxy group-terminated polyether (one havingat least 3 carbon atoms in a carbon linear moiety of repeating units)mono(meth)acrylate.

Further, in order to control the surface condition, shape and particlesize distribution of polymer particles in the polymer-dispersed polyol,a surfactant may be used at the time of polymerization of polymers. Asthe surfactant, a cationic surfactant, an anionic surfactant or anonionic surfactant may be used, and a nonionic surfactant is preferablyused, whereby e.g. excellent stability of the curving rate of a urethanefoam is achieved.

(Process for Producing Polymer-Dispersed Polyol (A1))

The process for producing the polymer-dispersed polyol (A1) may, forexample, be the following method.

A process of polymerizing a vinyl monomer by using a radicalpolymerization initiator in the presence of a base polyol.

As the base polyol, the polyol (a1) derived from a natural fat/oil maybe used alone, the polyoxyalkylene polyol (a2) may be used alone, or thepolyol (a1) derived from a natural fat/oil and the polyoxyalkylenepolyol (a2) may be used in combination.

The radical polymerization initiator may be a known radicalpolymerization initiator (for example, an azo compound or a peroxide).

Further, in order to adjust the viscosity, a solvent may be used at atime of polymerization.

Still further, in order to adjust the molecular weight of the polymerparticles, a solvent having a chain transfer property may be used, and acommercially available chain transfer agent may be initially added allat once at the time of polymerization or may be continuously addedsimultaneously with addition of the vinyl monomer.

The proportion of the polymer particles derived from the vinyl monomerin the polymer dispersed-polyol (A1) (100 mass %) is preferably at most50 mass %, more preferably from 3 to 50 mass %, particularly preferablyfrom 3 to 35 mass %.

The polymer dispersed-polyol (A1) has a hydroxy value of preferably from10 to 200 mgKOH/g, more preferably from 15 to 150 mgKOH/g.

The hydroxy value of the polymer dispersed-polyol (A1) is obtained bythe following formula based on the mass change before and after thepolymerization of the vinyl monomer.

Hydroxy value={hydroxy value of the polyol (a1) derived from a naturalfat/oil or hydroxy value of the polyoxyalkylene polyol (a2)}×{totalamount of the charge amount of the polyol (a1) derived from a naturalfat/oil and the charge amount of the polyoxyalkylene polyol(a2)}/{amount of the obtained polymer-dispersed polyol (A1)}.

The polymer-dispersed polyol (A1) has a weight average molecular weight(Mw) of preferably from 1,500 to 200,000, more preferably from 3,000 to100,000.

The polymer-dispersed polyol (A1) has a molecular weight distribution(Mw/Mn) of preferably from 1.2 to 30, more preferably from 1.5 to 20.

With respect to the polymer-dispersed polyol (A1) of the presentinvention as explained above, since the base polyol is a specific polyol(a1) derived from a natural fat/oil or polyoxyalkylene polyol (a2) usingthe polyol (a1) derived from a natural fat/oil as an initiator, it ispossible to produce a flexible polyurethane foam excellent in foamphysical properties and its appearance without having a polyol derivedfrom petroleum contained therein unlike a conventional polymer-dispersedpolyol using castor oil. Further, since a polyol derived from petroleumis not used in combination, the biomass degree is higher than theconventional polymer-dispersed polyol.

<Process for Producing Flexible Polyurethane Foam>

The process for producing a flexible polyurethane foam of the presentinvention is a process of reacting a polyol (A) with a polyisocyanate(B) in the presence of a catalyst (C) and a blowing agent (D).

(Polyol (A))

The polyol (A) contains at least the polymer-dispersed polyol (A1).

The polyol (A) preferably contains the polymer-dispersed polyol (A1) anda polyoxyalkylene polyol (A2).

The polyoxyalkylene polyol (A2) is preferably a polyoxyalkylene polyol(except for the polyoxyalkylene polyol (a2)) having an average number ofhydroxy groups of from 2 to 8 and a hydroxy value of from 20 to 160mgKOH/g.

When the polyoxyalkylene polyol (A2) has an average number of hydroxygroups of at least 2, the durability and the riding comfort of theflexible polyurethane foam tend to be good. When the polyoxyalkylenepolyol (A2) has an average number of hydroxy groups of at most 8, theflexible polyurethane foam becomes not so rigid, whereby the foamphysical properties such as elongation tend to be good.

The average number of hydroxy groups means the average number of activehydrogen atoms of an initiator.

When the polyoxyalkylene polyol (A2) has a hydroxy value of at least 20mgKOH/g, the viscosity will not be so high, whereby the workabilitytends to be good. When the polyoxyalkylene polyol (A2) has a hydroxyvalue of at most 160 mgKOH/g, the flexible polyurethane foam will not beso rigid, whereby the foam physical properties such as elongation tendto be good.

The polyoxyalkylene polyol (A2) has a weight average molecular weight(Mw) of preferably from 700 to 22,000, more preferably from 1,500 to20,000, particularly preferably from 2,000 to 15,000.

The polyoxyalkylene polyol (A2) can be obtained by subjecting analkylene oxide to ring-opening polymerization to an initiator in thepresence of a polymerization catalyst.

The polymerization catalyst may, for example, be an alkali metalcompound catalyst (for example, a sodium type catalyst, a potassium typecatalyst or a cesium type catalyst), a cationic polymerization catalyst,a double metal cyanide complex catalyst or a phosphazenium compound.

The sodium or potassium type catalyst may, for example, be sodium metal,potassium metal, a sodium or potassium alkoxide (such as sodiummethoxide, sodium ethoxide, sodium propoxide, potassium methoxide,potassium ethoxide or potassium propoxide), sodium hydroxide, potassiumhydroxide, sodium carbonate or potassium carbonate.

The cesium type catalyst may, for example, be cesium metal, a cesiumalkoxide (such as cesium methoxide, cesium ethoxide or cesiumpropoxide), cesium hydroxide or cesium carbonate.

The coordination anionic polymerization catalyst may be the samecoordination anionic polymerization catalyst mentioned as thepolymerization catalyst (b).

The cationic polymerization catalyst may be the same cationicpolymerization catalyst as mentioned as the polymerization catalyst (b).

The initiator may, for example, be ethylene glycol, diethylene glycol,propylene glycol, dipropylene glycol, neopentyl glycol, 1,4-butanediol,1,6-hexanediol, glycerin, trimethylolpropane, pentaerythritol,diglycerin, dextrose, sucrose, bisphenol A, ethylenediamine or apolyoxyalkylene polyol having a low molecular weight obtained by addingan alkylene oxide thereto.

The alkylene oxide may, for example, ethylene oxide, propylene oxide,1,2-butylene oxide, 2,3-butylene oxide or styrene oxide, and propyleneoxide or ethylene oxide is preferred. When the ethylene oxide is used,the proportion of the ethylene oxide in the alkylene oxide (100 mass %)is preferably at most 30 mass %, more preferably at most 25 mass %. Whenthe proportion of the ethylene oxide is at most 30 mass %, thereactivity of the polyol (A) with the polyisocyanate (B) becomes proper,and the moldability of the flexible polyurethane foam becomes good.

The polyoxyalkylene polyol (A2) may be used alone, or two or more typesmay be used in combination. When two or more types of polyoxyalkylenepolyols (A2) are used, the average number of the hydroxy groups, thehydroxy value and the weight average molecular weight of eachpolyoxyalkylene polyol (A2) is preferably in the above preferred range.

The ratio of the polymer-dispersed polyol (A1) to the polyoxyalkylenepolyol (A2), (A1)/(A2), is preferably in a range of from 10/90 to 90/10(mass ratio), more preferably from 15/85 to 80/20 (mass ratio). When theproportion of the polyoxyalkylene polyol (A2) is at least 10 mass %, themoldability of a flexible polyurethane foam is improved. When theproportion of the polyoxyalkylene polyol (A2) is at most 90 mass %,polyols derived from petroleum are decreased, whereby influence over theenvironment is suppressed.

The polyol (A) may contain another polyol other than thepolymer-dispersed polyol (A1) and the polyoxyalkylene polyol (A2).

Such another polyol may, for example, be a polyol (a1) derived from anatural fat/oil, a polyoxyalkylene polyol (a2), a polymer-dispersedpolyol (A3), a polyester polyol, a polycarbonate polyol, a naturalfat/oil containing hydroxy groups, or their modified products.

The polyol (a1) derived from a natural fat/oil is the above mentionedpolyol (a1) derived from a natural fat/oil, having no polymer particles.

The polyoxyalkylene polyol (a2) is the above mentioned polyoxyalkylenepolyol (a2), having no polymer particles.

The polymer-dispersed polyol (A3) is a polymer-dispersed polyol havingthe polyoxyalkylene polyol (A2) as a base polyol. By dispersing polymerparticles in the base polyol, the hardness, air flow and other physicalproperties of the flexible polyurethane foam can be improved.

The polymer of the polymer particles may be an addition polymerizationtype polymer or a condensation polymerization type polymer.

The addition polymerization type polymer may, for example, be ahomopolymer or copolymer of a vinyl monomer (for example, acrylonitrile,styrene, a methacrylate or an acrylate).

The condensation polymerization type polymer may, for example, bepolyester, polyurea, polyurethane or melamine.

By the presence of the polymer particles, the hydroxy value of thepolymer-dispersed polyol (A3) is usually lower than the hydroxy value ofthe base polyol. The average number of hydroxy groups, the weightaverage molecular weight (Mw) and the like of the polymer-dispersedpolyol (A3) are the numerical values for the base polyol.

The polyester polyol may, for example, be a polyester polyol obtained bycondensing a low-molecular-weight polyol and a carboxylic acid, or alactone polyol.

The low-molecular-weight polyol may, for example, be a C₂₋₁₀ dihydricalcohol (such as ethylene glycol or propylene glycol), a C₂₋₁₀ trihydricalcohol (such as glycerin, trimethylolpropane or trimethylolethane), atetrahydric alcohol (such as pentaerythritol or diglycerin), or asaccharide (such as sorbitol or sucrose).

The carboxylic acid may, for example, be a C₂₋₁₀ dicarboxylic acid (suchas succinic acid, adipic acid, maleic acid, fumaric acid, phthalic acidor isophthalic acid) or a C₂₋₁₀ acid anhydride (such as succinicanhydride, maleic anhydride or phthalic anhydride).

The lactone polyol may, for example, be an ε-caprolactone ring-openingpolymerized product or β-methyl-δ-valerolactone ring-opening polymerizedproduct.

The polycarbonate polyol may be one obtained by a dehydrochlorinationreaction of the low-molecular-weight polyol with phosgene, or by atransesterification reaction of the low-molecular-weight polyol withdiethylene carbonate, dimethyl carbonate, diphenyl carbonate or thelike.

The proportion of another polyol is preferably at most 40 mass % in thepolyol (A) (100 mass %). When the proportion of another polyol is atmost 40 mass %, the moldability of the flexible polyurethane foam can besatisfied while maintaining a high biomass degree.

(Another High-Molecular-Weight Active Hydrogen Compound)

As a compound to be reacted with the polyisocyanate (B), it is possibleto use the polyol (A) and another high-molecular-weight active hydrogencompound in combination.

Such another high-molecular-weight active hydrogen compound may, forexample, be a high-molecular-weight polyamine having at least 2 primaryamino groups or secondary amino groups; a high-molecular-weight compoundhaving at least one primary amino group or secondary amino group and atleast one hydroxy group; or a piperazine polyol.

The high-molecular-weight polyamine or the high-molecular-weightcompound may be a compound obtained by converting some or all hydroxygroups in a polyoxyalkylene polyol to amino groups; or a compoundobtained in such a manner that a prepolymer having isocyanate groups atits terminals, is obtained by reacting a polyoxyalkylene polyol with anexcess equivalent of a polyisocyanate compound, and the isocyanategroups of the prepolymer are converted to amino groups by hydrolysis.

The piperazine polyol is a polyoxyalkylene polyol obtained byring-opening polymerization of an alkylene oxide with piperazines.

The piperazines mean piperazine or a substituted piperazine wherein ahydrogen atom in the piperazine is substituted by an organic group suchas an alkyl group or an aminoalkyl group.

The piperazines are required to have at least two active hydrogen atoms.

In the piperazine polyol, two nitrogen atoms constituting a piperazinering constitute tertiary amines.

The piperazines may be piperazine, alkyl piperazines in which a hydrogenatom bonded to a carbon atom constituting the ring is substituted by alower alkyl group (such as 2-methylpiperazine, 2-ethylpiperazine,2-butylpiperazine, 2-hexylpiperazine, 2,5-, 2,6-, 2,3- or2,2-dimethylpiperazine or 2,3,5,6- or 2,2,5,5-tetramethylpiperazine) orN-aminoalkylpiperazines in which a hydrogen atom bonded to a nitrogenatom constituting the ring, is substituted by an aminoalkyl group (suchas N-(2-aminoethyl)piperazine). Preferred are substituted piperazines,and more preferred are substituted piperazines having at least 3nitrogen atoms in its molecule, such as piperazine having hydrogensubstituted by e.g. an aminoalkyl group.

Further, as the substituted piperazines N-substituted piperazines arepreferred, N-aminoalkylpiperazines are further preferred, andN-(aminoethyl)piperazine is particularly preferred.

An alkylene oxide to be ring-opening polymerized with such piperazines,is preferably an alkylene oxide having at least 2 carbon atoms, such asethylene oxide, propylene oxide, 1,2-butylene oxide, 2,3-butylene oxideor styrene oxide.

The molecular weight per functional group of such anotherhigh-molecular-weight active hydrogen compound is preferably at least400, more preferably at least 800. The molecular weight per functionalgroup is preferably at most 5,000.

The average number of functional groups of such anotherhigh-molecular-weight active hydrogen compound is preferably from 2 to8.

The proportion of such another high-molecular-weight active hydrogencompound is preferably at most 20 mass %, based on the total amount (100mass %) of the polyol (A) and another high-molecular-weight activehydrogen compound. When the proportion of such anotherhigh-molecular-weight active hydrogen compound is at most 20 mass %, thereactivity with the polyisocyanate (B) will not be too high, whereby themoldability or the like of the flexible polyurethane foam tends to begood.

(Polyisocyanate (B))

The polyisocyanate (B) may, for example, be an aromatic polyisocyanatecompound having at least 2 isocyanate compound groups, a mixture of twoor more of such compounds, or a modified-polyisocyanate obtained bymodifying it. Specifically, it may, for example, be a polyisocyanatesuch as tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI)or polymethylene polyphenyl polyisocyanate (name: crude MDI), or itsprepolymer type modified product, nurate modified product, urea modifiedproduct or carbodiimide modified product.

The total amount of MDI and crude MDI in the polyisocyanate (B) (100mass %) is preferably more than 0 mass % and at most 100 mass %, morepreferably from 5 to 80 mass %, particularly preferably from 10 to 60mass %. When the total amount of MDI and crude MDI is at most 80 mass %,the foam physical properties such as durability, touch of a foam, etc.become good.

The polyisocyanate (B) may be a prepolymer. The prepolymer may be aprepolymer of TDI, MDI or crude MDI with a polyol derived from a naturalfat/oil, a polyoxyalkylene polyol having an alkylene oxide ring-openingpolymerized to the polyol derived from a natural fat/oil, or a petroleumpolyoxyalkylene polyol.

The amount of the polyisocyanate (B) is preferably in a range of from 80to 125, particularly preferably in a range of from 85 to 120, by theisocyanate index. The isocyanate index is represented by 100 times ofthe number of isocyanate groups based on the total active hydrogen ofthe polyol (A), another high-molecular-weight active hydrogen compound,a crosslinking agent, water, and the like.

(Crosslinking Agent)

In the present invention, it is possible to use a crosslinking agent asa case requires.

The crosslinking agent is preferably a compound having a number ofactive hydrogen-containing groups of from 2 to 8 and a hydroxy value offrom 200 to 2,000 mgKOH/g. The crosslinking agent may be a compoundwhich has at least 2 functional groups selected from hydroxy groups,primary amino groups and secondary amino groups. Such crosslinkingagents may be used alone or in combination as a mixture of two or moreof them.

The crosslinking agent having hydroxy groups is preferably a compoundhaving 2 to 8 hydroxy groups, and a polyhydric alcohol, or alow-molecular-weight polyoxyalkylene polyol obtained by adding analkylene oxide to the polyhydric alcohol or a polyol having a tertiaryamino group may be mentioned.

Specific examples of the crosslinking agent having hydroxy groups may beethylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol,diethylene glycol, triethylene glycol, dipropylene glycol,monoethanolamine, diethanolamine, triethanolamine, glycerin, N-alkyldiethanol, a bisphenol A-alkylene oxide adduct, a glycerin-alkyleneoxide adduct, a trimethylolpropane-alkylene oxide adduct, apentaerythritol-alkylene oxide adduct, a sorbitol-alkylene oxide adduct,a sucrose-alkylene oxide adduct, an aliphatic amine-alkylene oxideadduct, an alicyclic amine-alkylene oxide adduct, a heterocyclicpolyamine-alkylene oxide adduct, and an aromatic amine-alkylene oxideadduct, and diethanolamine is referred, since hysteresis loss is suited.

The heterocyclic polyamine-alkylene oxide adduct is obtained byring-opening polymerization of an alkylene oxide with e.g. peperazine, ashort-chain alkyl-substituted piperazine (such as 2-methylpiperazine,2-ethylpiperazine, 2-butylpiperazine, 2-hexylpiperazine, 2,5-, 2,6-,2,3- or 2,2-dimethylpiperazine, or 2,3,5,6- or2,2,5,5-tetramethylpiperazine), or an aminoalkyl-substituted piperazine(such as 1-(2-aminoethyl)piperazine).

A crosslinking agent (an amine type crosslinking agent) having a primaryamino group or secondary amino group may, for example, be an aromaticpolyamine, an aliphatic polyamine or an alicyclic polyamine.

The aromatic polyamine is preferably an aromatic diamine. The aromaticdiamine is preferably an aromatic diamine having at least onesubstituent selected from an alkyl group, a cycloalkyl group, an alkoxygroup, an alkylthio group and an electron-attractive group, in anaromatic nucleus having amino groups bonded thereto, particularlypreferably a diaminobenzene derivative.

With respect to the above substituents except for theelectron-attractive group, from 2 to 4 substituents are preferablybonded to the aromatic nucleus having amino groups bonded thereto, morepreferably at least one at an ortho-position to the position where theamino group is bonded, particularly preferably, they are bonded at allpositions.

With respect to the electron-attractive group, 1 or 2 groups arepreferably bonded to the aromatic nucleus having amino groups bondedthereto. The electron-attractive group and another substituent may bebonded to one aromatic nucleus.

The alkyl group, alkoxy group and alkylthio group preferably have atmost 4 carbon atoms.

The cycloalkyl group is preferably a cyclohexyl group.

The electron-attractive group is preferably a halogen atom, atrihalomethyl group, a nitro group, a cyano group or an alkoxycarbonylgroup, particularly preferably a chlorine atom, a trifluoromethyl groupor a nitro group.

The aliphatic polyamine may, for example, be a diaminoalkane having atmost 6 carbon atoms, a polyalkylene polyamine, a polyamine obtained byconverting some or all hydroxy groups in a low-molecular-weightpolyoxyalkylene polyol to amino groups, or an aromatic compound havingat least 2 aminoalkyl groups.

The alicyclic polyamine may be a cycloalkane having at least 2 aminogroups and/or aminoalkyl groups.

Specific examples of the amine type crosslinking agent may be3,5-diethyl-2,4(or 2,6)-diaminotoluene (DETDA),2-chloro-p-phenylenediamine (CPA), 3,5-dimethylthio-2,4(or2,6)-diaminotoluene, 1-trifluoromethyl-3,5-diaminobenzene,1-trifluoromethyl-4-chloro-3,5-diaminobenzene, 2,4-toluenediamine,2,6-toluenediamine, bis(3,5-dimethyl-4-aminophenyl)methane,4,4-diaminodiphenylmethane, ethylenediamine, m-xylenediamine,1,4-diaminohexane, 1,3-bis(aminomethyl)cyclohexane and isophoronediamine, and preferred is diethyltoluenediamine (that is one type or amixture of two or more types of 3,5-diethyl-2,4(or 2,6)-diaminotoluene),dimethyithiotoluenediamine or a diaminobenzene derivative such asmonochlorodiaminobenzene or trifluoromethyldiaminobenzene.

The amount of the crosslinking agent is preferably from 0.1 to 10 partsby mass based on 100 parts by mass of the polyol (A).

(Catalyst (C))

The catalyst (C) is a catalyst to accelerate a urethanization reaction.

As the catalyst (C), an amine compound, an organic metal compound, areactive amine compound or a metal carboxylate may, for example, bementioned. Such catalysts (C) may be used alone or in combination as amixture of two or more of them.

As the amine compound, triethylenediamine, a dipropylene glycol solutionof bis-((2-dimethylamino)ethyl)ether and an aliphatic amine such asmorpholine may, for example, be mentioned.

The reactive amine compound is a compound wherein a part of the aminecompound structure is converted to a hydroxy group or an amino group soas to be reactive with an isocyanate group.

As the reactive amine compound, dimethylethanolamine,trimethylaminoethylethanolamine and dimethylaminoethoxyethoxyethanolmay, for example, be mentioned.

The amount of the amine compound catalyst or the reactive amine compoundcatalyst, is preferably at most 2.0 parts by mass, more preferably from0.05 to 1.5 parts by mass, per 100 parts by mass in total of the polyol(A) and another high-molecular-weight active hydrogen compound.

The organic metal compound may, for example, be an organic tin compound,an organic bismuth compound, an organic lead compound or an organic zinccompound. Specific examples may be di-n-butyltin oxide, di-n-butyltindilaurate, di-n-butyltin, di-n-butyltin diacetate, di-n-octyltin oxide,di-n-octyltin dilaurate, monobutyltin trichloride, di-n-butyltin dialkylmercaptan, and di-n-octyltin dialkyl mercaptan.

The amount of the organic metal compound is preferably at most 2.0 partsby mass, more preferably from 0.005 to 1.5 parts by mass, per 100 partsby mass in total of the polyol (A) and another high-molecular-weightactive hydrogen compound.

(Blowing Agent (D))

As a blowing agent (D), preferred is at least one member selected fromwater and an inert gas.

As the inert gas, air, nitrogen gas or liquified carbon dioxide gas maybe mentioned.

The amount of such a blowing agent may be adjusted depending on therequirement such as a blowing magnification.

When only water is used as the blowing agent (D), the amount of water ispreferably at most 10 parts by mass, more preferably from 0.1 to 8 partsby mass, per 100 parts by mass in total of the polyol (A) and anotherhigh-molecular-weight active hydrogen compound.

(Foam Stabilizer)

In the present invention, a foam stabilizer may be used as the caserequires.

The foam stabilizer is a component to form good foams.

The foam stabilizer may, for example, be a silicone type foam stabilizeror a fluorine type foam stabilizer.

The amount of the foam stabilizer is preferably from 0.1 to 10 parts bymass per 100 parts by mass in total of the polyol (A) and anotherhigh-molecular-weight active hydrogen compound.

(Cell Opener)

In the present invention, a cell opener may be used as the caserequires.

The use of the cell opener is preferred from the viewpoint of themoldability of the flexible polyurethane foam, specifically, thereduction of tight cells.

The cell opener is preferably a polyoxyalkylene polyol having an averagenumber of hydroxy groups of from 2 to 8, a hydroxy value of from 20 to100 mgKOH/g and a proportion of ethylene oxide of from 50 to 100 mass %.

(Other Formulating Agents)

Other formulating agents which may optionally be used, may, for example,be a filler, a stabilizer, a colorant and a flame retardant.

(Process for Producing Flexible Polyurethane Foam)

The process for producing a flexible polyurethane foam may be carriedout by a method in which a reactive mixture is injected into a mold,followed by foam-molding (a molding method) or a method in which areactive mixture is foamed in an open system (a slab method).

The reactive mixture is a mixture having the above mentioned componentsmixed.

Molding Method

As the molding method, preferred is a method of injecting the reactivemixture into a closed mold (a reaction-injection molding method) or amethod in which the reactive mixture is injected into a mold in an openstate, followed by closing. As the latter method, it is preferablycarried out by a method of injecting the reactive mixture into a mold byusing a low pressure machine or a high pressure machine.

The high pressure machine is preferably of a type to mix two liquids.One of the two liquids is the polyisocyanate (B) and the other liquid isa mixture of all components other than the polyisocyanate (B). Dependingon a case, it may be a type to mix at least three liquids by having thecatalyst (C) or the cell opener as a separate component (which isusually used as dispersed or dissolved in a part of ahigh-molecular-weight polyol).

The temperature of the reactive mixture is preferably from 10 to 40° C.When the temperature is at least 10° C., the viscosity of the reactivemixture will not be so high, whereby liquid mixing of the liquids tendsto be good. When the temperature is at most 40° C., the reaction ratewill not be too high, whereby the moldability or the like tends to begood.

The mold temperature is preferably from 10° C. to 80° C., particularlypreferably from 30° C. to 70° C.

The curing time is preferably from 1 to 20 minutes, more preferably from3 to 10 minutes, particularly preferably from 1 to 7 minutes. When thecuring time is at least 1 minute, curing will be sufficiently conducted.When the curing time is at most 20 minutes, productivity will be good.

Slab Method

The slab method may be a known method such as a one shot method, asemiprepolymer method or a prepolymer method. For the production of theflexible polyurethane foam, it is possible to use a known productionapparatus.

According to the above described process for producing the flexiblepolyurethane foam of the present invention, since the polymer-dispersedpolyol (A1) of the present invention having a higher biomass degree thana conventional polymer-dispersed polyol is used, it is possible toproduce a flexible polyurethane foam which has a higher biomass degreethan a conventional flexible polyurethane foam and is excellent in foamphysical properties and its appearance.

The flexible polyurethane foam produced by the process of the presentinvention can be used for an interior material for a vehicle (such assheet cushions, sheet backs, head rests or arm rests), an interiormaterial for a railway vehicle, beddings, mattresses, cushions, etc.

EXAMPLES

Now, the present invention will be described in further detail withreference to Examples, but it should be understood that the presentinvention is by no means limited thereto.

Examples 1 to 3, 5 to 12, 16 and 17 are Examples of the presentinvention, and Examples 4, 13 to 15 are Comparative Examples.

(Hydroxy Value)

The hydroxy values of polyols other than the polymer-dispersed polyol(A1) were measured in accordance with JIS K 1557 (titration method).

If the hydroxy value of the polymer-dispersed polyol (A1) is measured bythe titration method, the measurement tends to be hindered by a resinprecipitation, and therefore, it was obtained by measuring thepolymerization balance by calculation as mentioned below.

(Number Average Molecular Weight and Weight Average Molecular Weight)

The number average molecular weight (Mn) and the weight averagemolecular weight (Mw) were measured by the following process.

With respect to some types of monodispersed polystyrene polymers havingdifferent polymerization degrees, which are commercially available asstandard samples for molecular weight measurement, GPC was measured byusing a commercially-available GPC measuring device (tradename:HLC-8220GPC, manufactured by Tosoh Corporation), and based on therelation of the molecular weight and the maintaining retention time ofeach polystyrene, a calibration curve was prepared.

A sample was diluted by tetrahydrofuran to 0.5 mass % and passed througha filter of 0.5 μm, and GPC of the sample was measured by using the GPCmeasuring device.

By using the calibration curve, the GPC spectrum of a sample wasanalyzed by a computer, whereby the number average molecular weight (Mn)and the weight average molecular weight (Mw) of the sample wereobtained.

(Biomass Degree)

The biomass degree of polyols (including a polymer-dispersed polyol) wascalculated as a proportion (unit: %) of the mass of the polyol derivedfrom a natural fat/oil, based on the total mass of the raw materials(such as a polyol derived from a natural fat/oil, an alkylene oxide anda vinyl monomer) which constitute the polyol.

The biomass degree of the foam was calculated as a proportion (unit: %)of the mass of the polyol derived from a natural fat/oil contained inthe polyol, based on the total mass of the raw materials (such as apolyol, a polyisocyanate, a catalyst and a blowing agent) whichconstitute the reactive mixture.

The mass of the polyol derived from a natural fat/oil contained in thepolyol was calculated from {the mass of the polyol}×{the biomass degree(%) of the polyol}/100.

(Polyol (a1) Derived From a Natural Fat/Oil)

As the polyol (a1)) derived from a natural fat/oil, aerated soybean oil(tradename: Soyol R2-052F, manufactured by Urethane Soy Systems Company)obtained by a blowing method by using soybean oil as a raw material wasprepared. The hydroxy value was 45.3 mgKOH/g, the number averagemolecular weight (Mn) was 2,231, the weight average molecular weight(Mw) was 9,060, and the molecular weight distribution (Mw/Mn) was 4.061.

(Polymerization Catalyst (b))

As the polymerization catalyst (b), a zinc hexacyanocobaltate complexhaving tert-butyl alcohol coordinated (a DMC catalyst) was prepared asfollows.

Into a 500 mL flask, an aqueous solution comprising 10.2 g of zincchloride and 10 g of water was introduced. An aqueous solutioncomprising 4.2 g of potassium hexacyanocobaltate (K₃Co(CN)₆) and 75 g ofwater was dropwise added to the zinc chloride aqueous solution withstirring at 300 rpm over 30 minutes. Meantime, the solution mixture inthe flask was maintained at 40° C. After completion of the dropwiseaddition of the potassium hexacyanocobaltate aqueous solution, themixture in the flask was further stirred for 30 minutes, and then, amixture comprising 80 g of tert-butyl alcohol (hereinafter referred toas TBA), 80 g of water and 0.6 g of a polyol P was added thereto,followed by stirring at 40° C. for 30 minutes and further at 60° C. for60 minutes.

The polyol P is a polyoxypropylene diol which is obtained byring-opening polymerization of propylene oxide with propylene glycol inthe presence of a potassium hydroxide catalyst and is purified bydealkalization, and which has a hydroxy equivalent of 501.

The mixture thus obtained was filtrated under pressure (0.25 MPa) byusing a circular filter plate having a diameter of 125 mm and aquantitative filter paper for fine particles (No. 5C, manufactured byADVANTEC) to obtain a solid (a cake) containing a double metal cyanidecomplex.

Then, the cake was transferred into a flask, and a liquid mixturecomprising 36 g of TBA and 84 g of water was added thereto, followed bystirring for 30 minutes. Then, filtration under pressure was carried outunder the same conditions as mentioned above to obtain a cake.

The obtained cake was transferred into a flask, and a liquid mixturecomprising 108 g of TBA and 12 g of water was further added thereto,followed by stirring for 30 minutes to obtain a slurry in which thedouble metal cyanide complex catalyst was dispersed in the TBA-waterliquid mixture. To the slurry, 120 g of the polyol P was added, andthen, under reduced pressure, a volatile component was distilled at 80°C. for 3 hours, further at 115° C. for 3 hours, to obtain a slurry DMCcatalyst (the slurry of the polymerization catalyst (b)). Theconcentration (the active ingredient concentration) of the DMC catalyst(the solid catalyst component) contained in the slurry was 5.33 mass %.

(Polyoxyalkylene Polyol (a2))

Into a 500 ml stainless steel pressure proof reactor with a stirrer,248.2 g of the polyol (a1) derived from a natural fat/oil and 682 mg ofthe slurry of the polymerization catalyst (b) (36 mg as the solidcatalyst component) were introduced. After flushing inside of thereactor with nitrogen, the temperature was raised to 120° C., andvacuum-dehydration was carried out for 2 hours.

A mixture of 24.1 g of propylene oxide and 12.2 g of ethylene oxide wassupplied into the reactor over 40 minutes, followed by continuedstirring for 2 hours 30 minutes, and stop of pressure dropping wasconfirmed. Meantime, the inner temperature of the reactor was kept at120° C. and the stirring rate at 500 rpm to let the reaction proceed.

The appearance of the obtained polyoxyalkylene polyol (a2) was atransparent liquid at normal temperature. The hydroxy value was 43.8mgKOH/g, the number average molecular weight (Mn) was 2,338, the weightaverage molecular weight (Mw) was 8,516, the molecular weightdistribution (Mw/Mn) was 3.64, and the biomass degree was 87%.

EXAMPLE 1 (Polymer-Dispersed Polyol (A1-1))

Into a 2 litter glass bottle, a liquid mixture for dropwise addition,comprising 936 parts by mass of the polyoxyalkylene polyol (a2), 595.6parts by mass of acrylonitrile, 198.4 parts by mass of styrene and 30parts by mass of 2,2′-azobis(2-methylbutyronitrile) was added, and theglass bottle was attached to a rotary type quantitative supply pumpequipped with a tube (tradename: MP-1000, manufactured by TokyoRikakikai Co,. Ltd.).

The mass of a reactor comprising a 5 litter separable flask equippedwith a vacuum stirrer and a stirring stick was measured and regarded asthe tare (W_(o)). 2,240 parts by mass of the polyoxyalkylene polyol (a2)for initial charge was added thereto, and exit tubes for a condensertube and a liquid supply pump were attached. Then, the separable flaskwas immersed in an oil bath at 125° C. to adjust the inner temperatureto be 115±5° C. After the temperature became stable, the liquid mixturefor dropwise addition was dropwise added at a constant rate over 4 hours10 minutes. After dropwise addition, the reaction was subjected to agingfor 30 minutes. Then, the volatile substances such as unreacted monomerswere distilled out in vacuum for 2 hours at 120° C. under 3 torr toobtain the polymer-dispersed polyol (A1-1). The mass W₁ of the reactorand the obtained product was measured. The hydroxy value of thepolymer-dispersed polyol (A1-1) was calculated from the followingformula, whereupon it was 37.9 mgKOH/g.

Hydroxy value={the hydroxy value of the polyoxyalkylene polyol (a2) of43.8 mgKOH/g}×{the charged amount of the polyoxyalkylene polyol (a2) of3,176 parts by mass}/{the amount (W₁-W_(o)) of the obtainedpolymer-dispersed polyol (A1-1)=3,794 parts by mass}.

The polymer-dispersed polyol (A1-1) had a number average molecularweight (Mn) of 2,760, a weight average molecular weight (Mw) of 25,969and a molecular weight distribution (Mw/Mn) of 9.409.

The biomass degree of the polymer-dispersed polyol (A1-1) was calculatedfrom the following formula, whereupon it was 72.8%.

Biomass degree=the biomass degree of the polyoxyalkylene polyol (a2) of87%}×{the charged amount of the polyoxyalkylene polyol (a2) of 3,176parts by mass}/{the amount (W₁- W_(o)) of the obtained polymer-dispersedpolyol (A1-1)=3,794 parts by mass}.

The proportion of the polymer particles was calculated from thefollowing formula, whereupon it was 16.3 mass %.

Proportion of polymer particles=100−100×{the charged amount of thepolyoxyalkylene polyol (a2) of 3,176 parts by mass}/{the amount (W₁-W_(o)) of the obtained polymer-dispersed polyol (A1-1)=3,794 parts bymass}.

EXAMPLE 2 (Polymer-Dispersed Polyol (A1-2))

A polymer-dispersed polyol (A1-2) was obtained in the same manner as inExample 1 except that the polyoxyalkylene polyol (a2) was changed to thepolyol (a1) derived from a natural fat/oil. The hydroxy value(calculated value) was 37.7 mgKOH/g, the number average molecular weight(Mn) was 2,459, the weight average molecular weight (Mw) was 26,820, themolecular weight distribution (Mw/Mn) was 10.907, and the biomass degree(calculated value) was 83.3%. The proportion of polymer particles(calculated value) was 16.7 mass %. The biomass degree was calculatedregarding the biomass degree of the polyol (a1) derived from a naturalfat/oil as 100% in the same manner as in Example 1.

EXAMPLE 3 (Polymer-Dispersed Polyol (A1-3))

A polymer-dispersed polyol (A1-3) was obtained in the same manner as inExample 2 except that 595.6 parts by mass of acrylonitrile and 198.4parts by mass of styrene were changed to 198.4 parts by mass ofacrylonitrile and 595.6 parts by mass of styrene. The hydroxy value(calculated value) was 37.3 mgKOH/g, the number average molecular weight(Mn) was 2,860, the weight average molecular weight (Mw) was 28,885, themolecular weight distribution (Mw/Mn) was 10.1, and the biomass degree(calculated value) was 82.3%. The proportion of polymer particles was17.6 mass %.

EXAMPLE 4 (Polymer-Dispersed Polyol (A1-4)) (Polymer-Dispersed CastorOil)

A polymer-dispersed castor oil was obtained in the same manner as inExample 1 except that the polyoxyalkylene polyol (a2) was changed topurified castor oil (manufactured by Matsumoto Yushi-Seiyaku Co., Ltd.).The polymer-dispersed castor oil had a high viscosity, showedthixotropic properties and had a problem in flowability, and therefore,it was unsuitable for the production of a flexible polyurethane foam.The hydroxy value (calculated value) was 133.0 mgKOH/g, the numberaverage molecular weight (Mn) was 1,458, the weight average molecularweight (Mw) was 2,095, the molecular weight distribution (Mw/Mn) was1.436, and the biomass degree (calculated value) was 82.6%. Theproportion of polymer particles (calculated value) was 17.4 mass %. Thebiomass degree was calculated regarding the biomass degree of thepurified castor oil as 100% in the same manner as in Example 1.

EXAMPLE 5 (Polymer-Dispersed Polyol (A1-5)) (MicromonomerCopolymer-Dispersed Polyol)

Into a 0.5 litter glass bottle, a liquid mixture (for dropwise addition)comprising 210.6 parts by mass of the polyol (a1) derived from a naturalfat/oil, 134.01 parts by mass of acrylonitrile, 44.64 parts by mass ofstyrene, 5.4 parts by weight of BLEMMER VA (behenyl acrylate)manufactured by NOF Corporation and 6.75 parts by mass of2,2′-azobis(2-methylbutyronitrile) was added, and the glass bottle wasattached to a rotary type quantitative supply pump equipped with a tube(tradename: MP-1000, manufactured by Tokyo Rikakikai Co., Ltd.).

The mass of a reactor comprising a 1 litter separable flask equippedwith a vacuum stirrer and a stirring stick was measured and regarded asthe tare (W_(o)). 2,240 of parts by mass of the polyol (a1) derived froma natural fat/oil for initial charge was added thereto, and exit tubesfor a condenser tube and a liquid supply pump were attached. Then, theseparable flask was immersed in an oil bath at 125° C. to adjust theinner temperature to be 115±5° C. After the temperature became stable,the liquid mixture for dropwise addition was dropwise added at aconstant rate over 4 hours 10 minutes. After dropwise addition, thereaction was subjected to aging for 30 minutes. Then, the volatilesubstances such as unreacted monomers were distilled out in vacuum for 2hours at 120° C. under 3 torr to obtain the polymer-dispersed polyol(A1-5).

The obtained (A1-5) had a hydroxy value (calculated value) of 38.4mgKOH/g, a number average molecular weight (Mn) of 2,132, a weightaverage molecular weight (Mw) of 15,023, a molecular weight distribution(Mw/Mn) of 7.0, and a biomass degree (calculated value) of 83.3%.Further, the proportion of polymer particles was 15.3 mass %.

EXAMPLE 6 (Polymer-Dispersed Polyol (A1-6)) (Surfactant AdditionPolymerization Polymer-Dispersed Polyol)

A polymer-dispersed polyol (A1-6) having 5.4 parts by weight of asurfactant added was obtained in the same manner as in Example 5 exceptthat BLEMMER VA was changed to 5.4 parts by weight of W-1445manufactured by Nippon Nyukazai Co., Ltd.

The obtained (A1-6) had a hydroxy value (calculated value) of 38.2mgKOH/g, a number average molecular weight (Mn) of 2,210, a weightaverage molecular weight (Mw) of 22,447, a molecular weight distribution(Mw/Mn) of 10.2, and a biomass degree (calculated value) of 82.8%.Further, the proportion of the polymer particles was 15.7 mass %.

(Polyoxyalkylene Polyol(A2))

A polyoxypropyleneoxyethylene polyol having an average number of hydroxygroups of 4 and a hydroxy value of 28 mgKOH/g, and containing 13 mass %of a polyoxyethylene group at its terminals.

(Polymer-Dispersed Polyol (A3))

A polymer-dispersed polyol obtained by copolymerizing acrylonitrile withstyrene in the polyoxypropyleneoxyethylene polyol having an averagenumber of hydroxy groups of 3 and a hydroxy value of 34 mgKOH/g, andcontaining 14.5 mass % of a polyoxyethylene group at its terminals. Thepolymer-dispersed polyol had a hydroxy value of 24 mgKOH/g, and theproportion of the polymer particles was 35 mass %.

(Crosslinking Agent 1)

Diethanolamine.

(Crosslinking Agent 2)

A polyoxypropyleneoxyethylene polyol having an average number of hydroxygroups of 6 and a hydroxy value of 445 mgKOH/g, and containing 28 mass %of a polyoxyethylene group at its terminals.

(Cell Opener)

A polyoxypropyleneoxyethylene polyol having an average number of hydroxygroups of 3 and a hydroxy value of 48 mgKOH/g, and obtained by randomring-opening polymerization of propylene oxide with ethylene oxide in amass ratio of 20/80.

(Catalyst (C-1))

A 33% dipropylene glycol (DPG) solution of triethylenediamine(tradename: TEDA L33, manufactured by Tosoh Corporation).

(Catalyst (C-2))

A 70% DPG solution of bis-(2-dimethylaminoethyl) ether (tradename:TOYOCAT ET, manufactured by Tosoh Corporation).

(Foam Stabilizer)

A silicone type foam stabilizer (tradename: SF-2962, manufactured by DowCorning Toray Co., Ltd.).

(Blowing Agent (D))

Water.

(Polyisocyanate (B))

A mixture of TDI-80 (a mixture of 2,4-TDI/2,6-TDI=80/20 (mass ratio))and crude MDI in a mass ratio of 80/20 (tradename: CORONATE 1021,manufactured by Nippon Polyurethane Industry Co., Ltd.).

EXAMPLES 7 to 17

A polyol-containing mixture was prepared by mixing all materials exceptfor the polyisocyanate (B) with a formulation as shown in Table 1. Thepolyol-containing mixture was adjusted to have a liquid temperature of30±1° C. Separately, the polyisocyanate (B) was adjusted to have aliquid temperature of 25±1° C.

Then, to the polyol-containing mixture, the polyisocyanate (B) was addeduntil the isocyanate index shown in Table 1, followed by stirring for 5seconds by a high-speed mixer (3,000 rpm), and the mixture wasimmediately injected into a mold heated at 60° C. and sealed. As themold, an aluminum mold having an inside dimension of 400 mm in lengthand width×100 mm in height, was used.

Then, after curing at 60° C. for 7 minutes, a flexible polyurethane foamwas taken out from the mold. After crashing, the foam was left to standin a room (temperature: 23° C. and relative humidity: 50%) for 24 hours,followed by evaluation of foam appearance, foam physical properties andvibration characteristics.

Crashing is a step in which after the flexible polyurethane foam istaken out from the mold, the foam is continuously compressed to 75% ofthe foam thickness.

(Foam Appearance)

The skin portion and the core portion of the foam were visually observedand evaluated by the following standard.

◯: No problem at all.

◯ Δ: Very slight cell roughening observed.

Δ: Slight cell roughening observed.

Δ ×: Cell roughening observed in a part.

×: Cell roughening observed all around.

−: Collapse (squash) occurred.

(Foam Physical Properties)

As the foam physical properties, the overall density, the density at thecore portion, the 25% hardness (ILD hardness), the air flow, the reboundresilience, the rebound resilience at the core portion, the tearstrength, the tensile strength, the elongation, the dry set, the wet setand the hysteresis loss were evaluated.

Further, the density at the core portion and the rebound resilience atthe core portion were measured by using a sample cut out in a size of100 mm in length and width×50 mm in height from the center portion ofthe foam excluding the skin portion.

The overall density, the density at the core portion, the 25% hardness,the rebound resilience, the tear strength, the tensile strength, theelongation, the dry set, the wet set and the hysteresis loss weremeasured in accordance with JIS K6400 (1997 edition).

(Vibration Characteristics)

With respect to the vibration characteristics, the resonance frequency(unit: Hz), the transmissibility at resonance frequency (measurement ofabsolute displacement) and the transmissibility of 6 Hz were evaluated.The measurements were carried out in accordance with JASO B407-87. Asconditions for measuring the vibration characteristics, Tekken type(load: 490 N) was used as a pressing platen, and the vibrational totalamplitude was adjusted to be 5 mm.

TABLE 1 Formulation (part(s) by mass) Ex. 7 Ex. 8 Ex. 9 Ex. 10 Ex. 11Ex. 12 Ex. 13 Ex. 14 Ex. 15 Ex. 16 Ex. 17 Polyol (a1) derived from anatural fat/oil 22 30.4 38 Polyoxyalkylene polyol (a2) 2.7 8Polymer-dispersed polyol (A1-1) 24.5 Polymer-dispersed polyol (A1-2)24.5 38 47.2 Polymer-dispersed polyol (A1-3) 24.5 38 Polymer-dispersedpolyol (A1-5) 27 27 Polymer-dispersed polyol (A1-6) Polyoxyalkylenepolyol (A2) 72.8 62 52.8 72.8 62 67.5 64 47.9 35.1 45 45Polymer-dispersed polyol (A3) 14 21 26.9 28 28 Crosslinking agent 1 0.50.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Crosslinking agent 2 1.5 1.5 1.51.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Cell opener 1 1 1 1 1 1 1 1 1 1 1Catalyst (C-1) 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 Catalyst(C-2) 0.07 0.07 0.07 0.07 0.07 0.07 0.07 0.07 0.07 0.1 0.1 Foamstabilizer 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 1.2 1.2 Blowing agent (D)3.2 3.2 3.2 3.2 3.2 3.2 3.2 3.2 3.2 3.0 3 Polyisocyanate (B) (isocyanateindex) 100 100 100 100 100 100 100 100 100 100 100 Biomass degree (%) offoam 15 20 25 15 20 15 15 20 25 15 15 Foam appearance Skin portion ◯Δ ◯ΔΔX ◯Δ ◯Δ ◯Δ ◯Δ X — ◯Δ ◯Δ Core portion ◯ ◯ Δ ◯ ◯ ◯ ◯ X ◯ ◯ Overalldensity (kg/cm³) 62.6 62.5 61.8 62.2 62.4 62.2 62.3 62.4 59.1 59.3Density at the core portion (kg/cm³) 54.6 55.7 54.9 53.1 53.7 53.8 55.954.4 54.4 54.0 ILD hardness Initial thickness (mm) 98.4 98.3 98.5 98.297.8 98.1 98 98.1 96.4 97.3 (initial load: 0.5 kg) 25% (N/314 cm²) 198209 206 196 194 178 248 232 225 226 Air flow (L/min.) Core portion 66.7537.00 25.00 67.50 54.00 65.75 45.50 74.25 35.0 46.0 Rebound resilienceOverall 61 54 49 61 55 59 62 46 56 56 (%) Core portion 61 53 47 62 53 6065 56 63 63 Tear strength (N/cm) 4.7 3.6 3.1 4.1 3.9 4.5 4.9 5.4 6.5 6.4Tensile strength (kPa) 107.1 75.0 46.7 96.5 87.8 96.2 113.4 68.8 175.7166.7 Elongation (%) 100 79 60 107 100 103 104 82 109 109 Dry set (%)2.9 3.5 4.3 3.0 3.2 3.7 3.1 2.6 3.1 3.7 Wet set (%) 9.6 10.4 10.0 8.09.0 9.9 9.2 10.4 10.8 10.4 Hysteresis loss rate (%) 20.5 24.4 25.7 19.322.3 20.6 17.8 23.1 22.7 22.2 Vibration Resonance 3.45 3.67 3.85 3.53.67 3.65 3.23 3.45 3.70 3.78 Characteristics frequency (Hz)Transmissibility 3.95 3.2 2.7 3.4 3.08 3.4 4.03 4.1 3.32 3.74 atresonance frequency Transmissibility 0.66 0.76 0.9 0.61 0.75 0.76 0.50.62 0.66 0.66 of 6 Hz

The results in Table 1 show that each of the flexible polyurethane foamsin Examples of the present invention maintains the foam physicalproperties and the decrease in its foam appearance is suppressed evenwith a higher biomass degree.

On the other hand, with respect to each of the flexible polyurethanefoams in Comparative Examples, since the polymer-dispersed polyol of thepresent invention is not used, the foam appearance became bad when thebiomass degree was 20%, and collapse occurred when the biomass degreewas 25%.

INDUSTRIAL APPLICABILITY

The flexible polyurethane foam produced by the process of the presentinvention can be used for an interior material for a vehicle (such assheet cushions, sheet backs, head rests or arm rests), an interiormaterial for a railway vehicle, beddings, mattresses, cushions, etc.

The entire disclosure of Japanese Patent Application No. 2007-165014filed on Jun. 22, 2007 including specification, claims, and summary isincorporated herein by reference in its entirety.

1. A polymer-dispersed polyol obtained by polymerizing a vinyl monomerin the presence of the following polyol (a1) derived from a naturalfat/oil: Polyol (a1) derived from a natural fat/oil: a polyol derivedfrom a natural fat/oil, which is obtained by providing a natural fat/oilwith hydroxy groups by chemical reaction, and which has a hydroxy valueof from 20 to 250 mgKOH/g and a molecular weight distribution of atleast 1.2.
 2. The polymer-dispersed polyol according to claim 1, whereinthe polyol (a1) derived from a natural fat/oil is one obtained byblowing air or oxygen in a natural fat/oil to cause oxidativecrosslinking between unsaturated double bonds of the natural fat/oil andat the same time, to have hydroxy groups provided.
 3. Thepolymer-dispersed polyol according to claim 1, wherein the polyol (a1)derived from a natural fat/oil is one obtained by epoxidizingunsaturated double bonds of a natural fat/oil by having an oxidizingagent acted thereto, followed by ring-opening in the presence of anactive hydrogen compound to have hydroxy groups provided.
 4. Thepolymer-dispersed polyol according to claim 1, wherein the naturalfat/oil has an iodine value of from 50 to
 200. 5. The polymer-dispersedpolyol according to claim 1, wherein the natural fat/oil is soybean oil.6. The polymer-dispersed polyol according to claim 1, wherein the vinylmonomer contains acrylonitrile and styrene.
 7. The polymer-dispersedpolyol according to claim 16, wherein the polyoxyalkylene polyol (a2)has a hydroxy value of from 15 to 250 mgKOH/g and a molecular weightdistribution of from 1.2 to
 20. 8. The polymer-dispersed polyolaccording to claim 16, wherein the polymerization catalyst (b) is a zinchexacyanocobaltate complex having an organic ligand.
 9. Thepolymer-dispersed polyol according to claim 16, wherein the alkyleneoxide (c) is ethylene oxide and propylene oxide.
 10. A process forproducing a polymer-dispersed polyol, which comprises polymerizing avinyl monomer in the presence of the following polyol (a1) derived froma natural fat/oil: Polyol (a1) derived from a natural fat/oil: a polyolderived from a natural fat/oil, which is obtained by providing a naturalfat/oil with hydroxy groups by chemical reaction, and which has ahydroxy value of from 20 to 250 mgKOH/g and a molecular weightdistribution of at least 1.2.
 11. A process for producing a flexiblepolyurethane foam, which comprises reacting a polyol (A) containing thepolymer-dispersed polyol (A1) as defined in claim 1 and a polyisocyanate(B) in the presence of a catalyst (C) and a blowing agent (D).
 12. Theprocess for producing a flexible polyurethane foam according to claim11, wherein the polyol (A) further contains a polyoxyalkylene polyol(A2) having an average number of hydroxy groups of from 2 to 8 and ahydroxy value of from 20 to 160 mgKOH/g.
 13. The process for producing aflexible polyurethane foam according to claim 11, wherein the polyol (A)further contains the a polyoxyalkylene polyol (a2): a polyoxyalkylenepolyol which is produced by ring-opening polymerization of an alkyleneoxide (c) with the polyol (a1) derived from a natural fat/oil in thepresence of at least one polymerization catalyst (b) selected from thegroup consisting of a coordination anionic polymerization catalyst and acationic polymerization catalyst.
 14. The process for producing aflexible polyurethane foam according to claim 11, wherein foam-moldingis carried out in a sealed mold.
 15. The process for producing aflexible polyurethane foam according to claim 11, wherein the blowingagent (D) is water.
 16. The polymer dispersed polyol according to claim1, wherein said polyol is obtained by polymerizing a vinyl monomer inthe presence of polyol (a1) and a polyoxyalkylene polyol (a2): apolyoxyalkylene polyol which is produced by ring-opening polymerizationof an alkylene oxide (c) with the polyol (a1) derived from a naturalfat/oil in the presence of at least one polymerization catalyst (b)selected from the group consisting of a coordination anionicpolymerization catalyst and a cationic polymerization catalyst.